1. Field of Invention
The field of the currently claimed embodiments of this invention relates to imaging devices, and more particularly to imaging devices with one or more sensors for observation and tracking of a patient and one or more tools.
2. Discussion of Related Art
In image-guided interventions, the tracking and localization of imaging devices and medical tools during procedures is exceptionally important and considered the main enabling technology in image-guided surgery (IGS) systems. Most tracking technologies may be categorized into the following groups: 1) mechanical-based tracking including active robots (e.g., DaVinci robot) and passive-encoded mechanical arms (e.g., Faro mechanical arms), 2) optical-based tracking, 3) acoustic-based tracking, and 4) electromagnetic (EM)-based tracking.
Ultrasound is one useful imaging modality for image-guided interventions including ablative procedures, biopsy, radiation therapy, and surgery. In the literature and in research labs, ultrasound-guided intervention research is performed by integrating a tracking system (either optical or EM methods) with an ultrasound (US) imaging system to, for example, track and guide liver ablations, or in external beam radiation therapy [E. M. Boctor, M. DeOliviera, M. Choti, R. Ghanem, R. H. Taylor, G. Hager, G. Fichtinger, “Ultrasound Monitoring of Tissue Ablation via Deformation Model and Shape Priors”, International Conference on Medical Image Computing and Computer-Assisted Intervention, MICCAI 2006; H. Rivaz, I. Fleming, L. Assumpcao, G. Fichtinger, U. Hamper, M. Choti, G. Hager, and E. Boctor, “Ablation monitoring with elastography: 2D in-vivo and 3D ex-vivo studies”, International Conference on Medical Image Computing and Computer-Assisted Intervention, MICCAI 2008; H. Rivaz, P. Foroughi, I. Fleming, R. Zellars, E. Boctor, and G. Hager, “Tracked Regularized Ultrasound Elastography for Targeting Breast Radiotherapy”, Medical Image Computing and Computer Assisted Intervention (MICCAI) 2009]. Current commercial systems may include integrating an EM tracking device into high-end cart-based US system. Small EM sensors may be integrated into the ultrasound probe, and similar sensors may be attached and fixed to the intervention tool of interest.
Limitations of the current approach on both the research and commercial sides may be attributed to the available tracking technologies and to the feasibility of integrating these systems and using them in clinical environments. For example, mechanical-based trackers are considered expensive and intrusive solutions, i.e. they require large space and limit user motion. On the other hand, acoustic tracking does not provide sufficient navigation accuracy. Optical and EM tracking technologies require intrusive setups with a base camera (in case of optical tracking methods) or a reference EM transmitter (in case of EM methods). Additionally, optical rigid-body or EM sensors have to be attached to the imager and all needed tools, hence offline calibration and sterilization steps are required. Furthermore, none of these systems natively assist multi-modality fusion registration (e.g. between pre-operative CT/MRI plans and intra-operative ultrasound), and do not contribute to direct or augmented visualization either. Thus, there remains a need for improved combined imaging and registration devices for use in image-guided surgery.